The present invention relates broadly to apparatus and methods for the nondestructive testing of workpieces, equipment, and other industrial items. More particularly, the present invention relates to an apparatus for testing the sharpness of edges of workpieces comprised in household appliances and other consumer goods.
Various hardware and equipment such as appliances and other such consumer goods often comprise workpieces formed from metal. Such metal workpieces are configured into shapes having edges that may be considered sharp and, for example, when such workpieces with sharp edges are comprised in a household appliance, the sharp edges may snag the clothing of a person using the household appliance. Thus, it is known to use a sharp edge test apparatus to assess the degree of sharpness of sharp edges associated with household appliances or other equipment.
Underwriters Laboratories, which is an independent, not-for-profit product safety certification organization that tests products, has promulgated a test for testing edge sharpness in an effort to encourage a uniform standard for edge sharpness. This test for testing edge sharpness promulgated by Underwriters Laboratories is denominated Test For Sharpness Of Edges On Equipment and has been made available as UL Form 1439 (“UL 1439”) (ISBN 0-7629-0275-2). A general test apparatus specified by Underwriters Laboratories for performing a test for testing edge sharpness includes two sensing tapes layered on top of an indicating tape to provide a three-layer tape arrangement on the test head of the sharp edge test apparatus. The sharp edge test apparatus uses an arm to support the test head and the arm is spring-biased to apply a predetermined force to the edge of the appliance as it is moved therealong and, if the tape is cut, an analysis is conducted and a subjective determination made whether or not the edge has sufficiently cut the tape to render the edge dangerous and therefore fail the test. A test apparatus having a sensing tape carried on a test head is available from Excellent Technology Co. of Hong Kong and features removable test heads to speed up ongoing testing operations.
While a test for testing edge sharpness such as the test just described may yield useful results, tests of this type involving a visual observation by a test performer that the sensing tape has been cut disadvantageously bring with them an element of subjective interpretation—namely, a subjective interpretation by the test performer as whether a sensing tape has, in fact, been cut or has not been cut. It would therefore be desirable if a test for testing edge sharpness could be performed that diminishes, if not entirely eliminates, the necessity for a test performer to subjectively interpret the test results as to whether a sensing tape has been sufficiently cut or not cut when deployed during a test for testing edge sharpness.